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| Loss
of tension |
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 Cause:
Blade being used on misaligned saw.
Remedy: Check for proper saw alignment.
Cause: Blade is excessively hard for the material being
cut, creating stress on the steel centre.
Remedy: Make certain blade is correct for material being
cut. (Consult manufacturer's recommendation chart or phone our technical
helpline)
Cause: Material slippage causing blade to twist and become
kinked or bent.
Remedy: Maintain tight grip on material while sawing.
Cause: Utilising blade flanges that are under size or not
the same diameter, creating uneven pressure on the centre.
Remedy: Make certain blade flanges are proper size and identical
diameter.
Cause: Blade being used at incorrect RPM.
Remedy: Make certain blade shaft is turning at the proper
RPM by using a tachometer. This is especially important with concrete
saws.
Cause: Blade improperly mounted on arbor shoulder hence
becoming distorted when flanges are tightened.
Remedy: Hold blade securely on arbor shoulder until outside
flange and nut are firmly tightened.
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| Undercutting |
 Cause:
Undercutting is a condition in which the steel centre wears faster
than the diamond segment, especially in the areas where the segment
and core are joined. The condition is caused by a highly abrasive
material grinding against the blade during the sawing operation. Usually
materials containing sand are responsible for this condition (see
section on SEGMENT LOSS).
Remedy: The flow of swarf (abrasive cuttings) must be distributed
over a wider area, away form the critical segment area. Many times
this can be accomplished by using undercut protectors specially positioned
around the steel centre to change the pattern of constant abrasion.
Although successful in most cases, undercut protectors do not provide
100% protection. Use high water flow to wash out swan.
Cause: With a floor saw, sawing all the way through the
material, allowing the coolant water to escape from the kerf and
thus overheating the blade.
Remedy: Set the cutting depth several millimetres less than
the total thickness of the slab, thus allowing water to stay in
the kerf.
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| Uneven
Segment Wear |
|
 Cause:
Segments worn on one side reducing side clearance, usually caused
by misalignment of the saw or a lack of sufficient water on both
sides of the blade.
Remedy: Check saw alignment. Clean water system, making certain
that water is properly applied to the leading edge of the blade
flanges. Check to see if pump is supplying sufficient even water
(See EXCESSIVE WEAR section).
Cause: Blade is worn out-of-round due to bad bearings, worn
arbor, missing bushing, arbor hole larger than arbor, cleanliness
of or damage to flange surfaces or excessive dulling condition.
(See section of EXCESSIVE WEAR).
Remedy: Replace bearing or worn arbor as required. Inspect
flanges for damage and foreign materials; replace if necessary.
Do not remove drive pins when supplied with blade flanges.
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| Cracked
Segments |
|
 Cause:
Blade bond is too hard for the material being cut.
Remedy: Use blade with a softer bond.
Cause: Cutting speed too fast.
Remedy: Reduce speed of advance.
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| Excessive
Wear |
|
 Cause:
Using too soft a bonded blade on highly abrasive material (e.g using
a concrete blade to cut asphalt or green concrete).
Remedy: Consult one of our technical representatives
for a blade recommendation for cutting abrasive materials.
Cause: Lack of sufficient coolant to the blade. Often detected
by excessive wear in the centre of the segment (Note: In both cases
diamonds will usually be highly exposed)
Remedy: Clean up water coolant system, Make sure water pump
is functioning correctly.
Cause: Wearing out-of-round accelerates wear. Usually caused
by bad bearings, worn shaft or using a blade with too hard a bond
for the material being cut.
Remedy: Check bearings and arbor, if worn replace with new
parts before installing another blade.
Cause: Insufficient power caused by loose v-belts, inadequate
voltage or improper RPM's.
Remedy: Tighten belts (taut). Replace worn belts. Check supply
voltages (use correct extension cords).
Cause: Cutting speed too fast. Remedy: Reduce rate of advance.
Cause: Blade not perpendicular to material being cut.
Remedy: Check blade shaft flanges to ensure proper alignment
of the blade and equipment.
Cause: Blade shaft RPM too low.
Remedy: Check operating RPM of blade shaft. If necessary
change equipment or modify' blade shaft speed.
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| Segment
Loss |
|
 Cause:
The material slips during cutting which twists or jams the segments
loose.
Remedy: Hold the material securely while cutting.
Cause: Blade is too hard for the material being cut, causing
excessive dullness, which causes the segment to pound off or fatigue.
Remedy: Use a softer blade bond specification.
Cause: Worn blade flanges fail to provide proper support
causing the blade to deflect.
Remedy: Replace both blade flanges.
Cause: Out of round blade rotation resulting in pounding
caused by worn arbor or bad bearings in the shaft.
Remedy: Replace worn arbor and/or bearings
Cause: Overheating. Usually easily detected by bluish colour
on steel centre, generally confined to the area where the segment
was lost.
Remedy:: Check the water system for blocked water passages.
Test pump to see if it is functioning correctly. For dry cutting
it may be necessary to make shallower cuts and allow the blade to
run free every few minutes to let the air cool it.
Cause: Segment is subjected to sudden, sharp jolting whilst
moving the machine or when contacting the material being cut.
Remedy: Avoid jarring the blade when transporting the machine.
Contact the material being cut with slow even, reciprocal movements.
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| Overheated
Blade |
|
 Cause:
Adequate coolant was not provided.
Remedy: Check water supply for adequate volume and for obstructions
through water system. Use dry blades ONLY for shallow cutting (2-5cm
deep) or step cutting. Allow blade to run free every 10-15 seconds
to increase airflow cooling.
Cause: Using improper bond specification for the material
being cut.
Remedy: Contact Diamond Discs Direct technical helpline for
an accurate bond specification recommendation.
Cause: Cutting speed too fast.
Remedy: Reduce speed of advance.
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| Arbor
Hole Out Of Round |
|
 Cause:
Saw arbor badly worn due to blade being improperly seated.
Remedy: Be certain the blade is properly seated on the arbor
before tightening the flange.
Cause: Blade flanges not properly tightened premitting blade
to rotate or shaft.
Remedy: Always wrench tighten arbor nut; never hand tighten.
Always use hex nuts, not wing nuts.
Cause: Blade flanges or arbor shaft worn and not providing
blade suppo
Remedy: Check blade flanges or arbor shaft for wear, foreign
matter and proper tightness. Both flanges should be tightened no
less than the manufcturers recommended figure. eplace any worn machine
parts.
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| Eccentricity |
|
 Cause:
The blade bond is too hard for the material being cut. The harder
bond retains the diamonds and they begin to round off, causing the
blade to become dull. Instead of cutting the blade begins to pound',
causing the blade to wear out of round.
Remedy: Change to a softer bond of blade which will wear
away more readily allowing new, sharp diamonds and hence a new cutting
edge to be exposed.
Cause: The saw blade shaft may have a groove scored in it,
caused by the blade spinning between the flanges. A new blade installed
on the arbor shaft will seat into the groove and immediately run
eccentrically when the saw starts.
Remedy: Replace the worn shaft.
Cause: If the blade shaft bearings are worn, the shaft and
mandrel will run eccentrically, causing the blade to wear out of
round. This happens most often with concrete saws when proper lubrication
of the bearings is neglected.
Remedy: Install new blade shaft bearings. In some cases it
may also be necessary to replace the blade shaft if it is worn or
out of alignment.
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| Blade
Won't Cut |
|
 Cause:
Blade bond too hard for the materials being cut (eg abrasive material
or asphalt blade being used to cut concrete)
Remedy: Contact Diamond Discs Direct technical helpline for
an accurate bond specification recommendation.
Cause: Insufficient power to permit blade to cut properly.
(Loose v-belts, low voltage, insufficient horsepower motor).
Remedy: Check belts, voltage and motor output.
Cause: Blade has become dull due to continuous use on fairly
hard or vitrified material.
Remedy: Redress blade on an abrasive material until diamonds
become exposed again E.g run the blade through a 'breeze block'.
This may be necessary occasionally, however if dullness occurs too
often, the blade bond is likely to be too hard for the material
being cut.
Cause: Blade becomes glazed due to inadequate pressure against
the material being cut.
Remedy: Ensure adequate but not excessive pressure to keep
the blade sharpened.
Cause: Blade segments appear to still have plenty of life,
but will not cut.
Remedy:: Some harder bonded blades designed for abrasive
materials require a non-diamond bearing section or 'free-back' at
the base of the segment, for better adherence to the steel centre.
A blade used to this stage has worn out in the normal manner and
should be replaced.
Cause: Blade becomes glazed due to excessive RPM.
Remedy: Match blade diameter and specification to machine
(see our diameter/rotational speed recommendation
chart).
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| Cracked
Core |
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 Cause:
Blade bond too hard for the material being cut.
Remedy: Use correct blade with a softer bond.
Cause: Excessive cutting pressure, or jamming and twisting
of the blade in the cut can cause the blade core to bend or flex.
When subjected to extreme stress and metal fatigue, the blades steel
core will eventually crack.
Remedy: The saw operator should use steady reciprocal infeed
pressure and be careful not to twist or jam the blade in the cut.
Cause: Overheating through inadequate water supply or improper
use of dry cutting blades.
Remedy: Use adequate water to cool wet-cutting blades (eg 7-18
litres per minute for concrete saws). Allow adequate airflow around
dry-cutting blades to prevent overheating.
Cause: RPM too high.
Remedy: Check operating RPM of blade shaft. Change equipment
or blades if necessary. NEVER USE A BLADE WITH A CRACKED CORE!
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